Heatable covering system

ABSTRACT

The present invention relates to a heatable covering system for floors, ceilings, and walls. The covering system comprises covering panels which at least on one longitudinal edge comprise coupling means in order to be able to join covering panels with each other wherein the covering panels are provided with electrical heating means and have electrical contacting means in order to electrically contact the panels.

The present invention relates to a heatable covering system for floors,ceilings and walls according to the preamble of claim 1. A furtheraspect relates to a heating means for a covering system.

For heating of floor surfaces, different methods are known from theprior art. A popular floor heating consists of a number of pipes ortubes, which are arranged meander-shaped across a floor and throughwhich a heating fluid, usually hot water, streams. Onto these heatingpipes or tubes, the real floor cover, for example a parquet or tilefloor, is laid and which is heated by means of the hot pipes.

Floor heatings are panel heatings which allow a uniform and therewithcomfortable heat distribution. However, conventional floor heatings,like the above described, are expensive with respect to material costsand also with respect to its installation and which normally can be onlyinstalled by accordingly trained experts.

From the European patent EP 105 5 087 B1, a heatable covering system forfloors is known, which consists of a number of metal plates in whichchannels are incorporated. The metal plates are laid on a floor in sucha manner that the channels are connected with each other. Then, intothese channels a heating cable is meander-shaped inserted. The heatingcable is self-adjusting and provided with an integrated thermalprotection in order to eliminate the risk of excessive heating. Onto themetal plates and the heating cable which is arranged in the channelswithin the plates, then, a usual floor cover, for example ceramic tiles,can be laid.

From the U.S. Pat. No. 6,737,611 B2, an electrically conducting mat isknown, which heats itself while applying a potential. The mat consistsof a semi-crystalline polymeric and an electrically conducting fillmaterial and due to its small thickness can be laid below a floor cover.The heat mat is flexible and is offered in a rolled-up condition. Duringlaying the heat mat, it has only to be un-rolled above a floor andaccordingly fixed and electrically connected.

An object of the invention is to provide a heatable covering system forfloors, ceilings and walls by which the covering panels are providedwith electric heating means. Further, it is an object of the inventionto be able to electrically connect such covering panels provided withelectric heating means in an easy manner. A further aspect relates to anelectric heating means for a covering system.

These and other objects, which during reading the following descriptionwill be named or can be recognized by a person skilled in the art, aresolved by means of a heatable covering system according to claim 1.

In one embodiment, the heatable covering system for floors, ceilings andwalls, comprises covering panels with a decorative top side and a bottomside, for example laminate floor panels. In this case, the coveringpanels are provided with coupling means at least on one longitudinaledge in order to be able to join covering panels with each other. Thecovering panels are provided with electrical heating means and thecovering panels have suitable configured electric contacting means whichallow an electric connection between the electric heating means of twoand more covering panels. Preferably, the electric heating means arearranged at the bottom side of the covering panels, i.e. in the spacebetween the covering panels and the floor or the wall which should becovered with the panels. In order to allow a as simple as possibleelectric connection between two panels, it is indented that the electriccontacting means are arranged at least partially on the coupling meansof the panels so that by means of connecting of corresponding couplingmeans of two panels also an electric connection between the electricheating means of these panels is producible.

In a preferred embodiment, the coupling means are provided as groove andtongue elements, which are provided complementary to each other so thata tongue can be inserted with its longitudinal edge of a first coverpanel in a respectively provided groove at a longitudinal edge of asecond cover panel. In order to be able to connect several cover panelswith each other, the coupling means are preferably provided at least ontwo opposite longitudinal sides of the covering panels, whereinparticularly always a groove lies opposite to a tongue. The couplingmeans preferably extend over the full length of a longitudinal side.

In order to achieve a good electric contact, the electric contactingmeans preferably extend over substantially the full length of thecoupling means. In this manner, it is possible to cut the covering panelto any length in order to adopt them to the special lay-requirementswithout that the electric contactability is lost.

The contacting means consist, for example, of stripe-shaped electricallyconducting elements. For example, they can consist of an electricallyconducting metal foil, which consists of, for example, copper, aluminiumor high-grade steel. In a further exemplary embodiment, the electricallyconducting foil consists of tinned copper strip.

For mounting the contacting means onto the coupling means, for example,these can be pressed and/or glued on the coupling means. The appliedadhesive material is preferably electrically conductive. In case thecontacting means consist of strip-shaped electrically conductingelements, these are preferably pressed onto the coupling means in such amanner that they are fixed at the coupling means by means of a tightfit. In case the coupling means are made of complementary providedgroove and tongue elements, the strip-like elements can be laid orpressed, respectively, for example, around the tip of the tongue. Anadvantageous adhesive connection can be realized, for example, by meansof an adhesive tape, which preferably is adhesive on both sides. In thismanner, it is possible to make the adhesive bonding of the contactingmeans on the coupling means easier, for example by applying the adhesivetape at first on the contact means, for example an electricallyconducting metal foil and then by arranging and gluing the compoundconsisting of contacting means and adhesive tape on the coupling means.Of course, here it is also possible to press the contacting meansadditionally with the coupling means in order to achieve a even betterconjunction between contacting means and coupling means.

In a particular advantageous embodiment, the coupling means consist ofcomplementary provided groove and tongue elements and the contactingmeans of electrically conducting metal foil. The inner surfaces of thelower flank of the groove elements are thereby at least partiallycovered by an electrically conducting metal foil. By the tongueelements, the lower sides of the tongue elements are at least partiallycovered with a metal foil. In case, two covering panels withcomplementarily provided groove and tongue elements are mechanicallyconnected with each other by inserting the tongue of the one coveringpanel into the groove of the other covering panel, in this mannersimultaneously and beside any additional effort, an electric connectionbetween two covering panels is achieved. As soon as the tongue of onecovering panel is inserted into the complementarily provided groove of afurther covering panel, even automatically and simultaneously, theelectric connection by means of the electrically conducting metal foilsarranged within the groove of one panel and at least partially on thetongue of the other panel is provided.

A further aspect relates to electric heating means for covering panels,which particularly can act good together with the above disclosedcontact means. However, the heating means can also act together withother common contact means. The electric heating means of the coveringpanels preferably consists of a panel heating. This can be arranged onthe top side or bottom side of the covering panels, however preferablyit is arranged on the bottom side of the covering panel. If in thefollowing the top side and bottom side of the covering panel isdiscussed, it should be clear that this does not necessarily mean thatthe electrical heating means are arranged as single layer at the bottomor top side of the covering panel or that they have to be arrangeddirectly at the bottom or top side. On the contrary, further layers,particularly décor layers and abrasion-proof layers, can be provided atthe top side and layers for sound-absorption or layers for thermalinsulation at the bottom side can be provided.

The electric panel heating preferably consists of an electricallyconducting thin film. For example, this can be built from electricresistance wires. The resistance wires can be provided, for example, bymeans of a web made of thin conducting copper wires, which warm upduring electric application.

In a preferred embodiment, the electric panel heating consists of anelectrically conducting coating. For example, the electric panel heatingcan be applied by means of spray coating, foil coating, doctor bladecoating, screen coating or inkjet coating or a combination of thesemethods. Preferably, the electrically conducting coating is made of afluid, which after coating the covering panels is preferably dryable. Ina preferred embodiment, the electrically conducting fluid consists ofgraphite varnish or carbon varnish. Such varnish can be commerciallyobtained, for example, from the company CRC Industries GmbH, Germany. Itis also, for example, possible that the fluid is provided with carbon orgraphite particles in order to improve the electric conductibilityand/or in order to make the fluid electrically conducting. In a furtheradvantageous embodiment, the fluid comprises nano-scale electricallyconducting particles or so called multi-walled-carbon-nano-tubes.

The energy supply should be happen with an alternating voltage less than42 V, particularly with a voltage of 38 V. Thereby, the electrical powerinput is preferably not greater than 120 Watt per m². A covering system,which is provided with electrical heating means, is preferably providedwith an automatic temperature control. Thereby, the temperature controlkeeps the surface temperature of the covering panel in the range of 18°C. to 32° C.

The covering panels can, for example, be laminate panels, veneer panelsor parquet panels. Such covering panels are preferably used for flooringand are commercially obtainable in a variety of embodiments, qualitiesand sizes.

In order to increase the effectivity of a covering system with thedisclosed electric heating means, below the heating means preferably aninsolating layer for insolation is arranged. The insolating layer forinsolation consists, for example, of an electrically non-conductingfleece. As material for the heat-insolation layer, practically allheat-insolating materials, which are usually used for interiorconstruction and for the laying of floorings, are applicable. Thereby,also electrically conducting materials are conceivable; however, in thiscase they have to be electrically insolated from the heating system andfrom the electrical contact means. This, for example, can be done bymeans of a further electrically, non-conducting layer, which is arrangedbetween insolating layer and possibly adjacent electrical contactingmeans or electrical heating means. In an exemplary embodiment, below theheating means, an insolating layer for insolation is arranged, whichconsists of an electrically non-conducting, non-woven fleece, having athickness of more as 1 mm.

The electrical heating should have a sheet resistance between 100 to 500W per m², particularly between 250 to 300 W per m². This is particularlytrue for the previously mentioned electrically operated panel heatingsmade of electrically conducting thin films, for example, layers made ofresistance wires or electrically conducting coatings, for example,graphite varnish or carbon varnish.

In an advantageous embodiment, the bottom sides of the covering panelsare provided with a sound-absorbing layer. From the field of laminate,veneer and parquet floorings, a person skilled in the art knows a numberof sound-absorbing materials and laying methods therefore. Thesound-absorbing layer can, for example, be arranged between the bottomside of the covering panel and the electrical heating layer. In anadvantageous embodiment, the covering panel comprises a sound-absorbinglayer and also a heat-insolating layer. Starting from the bottom side ofthe covering panel, the covering advantageously comprises the followinglayer system: a sound-absorbing layer; an electric panel heating, and aheat-insolating layer.

In the following, a detailed description of the figures is provided.

FIG. 1 shows a schematic cross-section view of a covering panel;

FIG. 2 shows a schematic cross-section view of a covering panel with anadditional insolating layer;

FIG. 3 shows a schematic cross-section view of a covering panel with anumber of further layers;

FIG. 4 is a schematic illustration of the layer structure of anembodiment of a covering panel;

FIG. 5 is a schematic illustration of a covering system;

FIG. 6 is a further schematic illustration of a covering system; and

FIG. 7 is a schematic illustration an alternative electric contactmeans.

In FIG. 1, a schematic cross-section view of an exemplary covering panel10 is shown which is intended for use in a covering system. Theexemplary covering panel 10 of the FIGS. 1 to 3 is a laminate panel fora floor. Such laminate panels usually have a rectangular shape whereinthe both longitudinal edges are provided with groove and tongueelements. The short cross sides of such a covering panel can also beprovided with similar or also with different coupling means. In thismanner all four edges of the covering panels are provided with couplingmeans so that this can be connected in a covering system at all foursides with further covering panels in order to be able to cover a largerarea. The covering panel 10 has a top side 11 and a bottom side 12. Thetop side 11 can be covered with further layers made of differentmaterials. In case of the laminate panel this is usually at least adécor layer consisting of a printed special paper and an above arrangedoverlay layer which is particularly abrasive resistant and serves asprotecting layer. At the bottom side 12 also further layers can bearranged, for example, layers for sound-absorbing or layers forheating-insolation. At both longitudinal sides of the covering panel 10coupling means in the form of tongue 13 and groove 14 are provided.Tongue and groove are complimentarily to each other provided so that incase two covering panels 10 should be joint with each other, a tongue 13of the covering panel can be inserted in a groove 14 of the othercovering panel. The shown embodiment of tongue and groove is onlyexemplary and there are a large number of different tongue and grooveshapes known from the prior art which can also be used with the presentinvention.

In the embodiment shown in FIG. 1, the tongue 13 is provided withcontacting means 15. The contacting means 15 extends, following theshape of the tongue, from the top side 16 of the tongue around the tip18 of the tongue over the bottom side 17 of the tongue to the bottomside 12 of the covering panel 10. The contacting means 15 is, forexample, a thin strip of an electrically conducting material, forexample, a thin copper strip. The strip is preferably so thin andflexible respectively that it can be curved around the shape of thetongue or the groove without big effort. The strip 15 preferably extendsover the full length of the tongue, i.e. over the total length of thelongitudinal side of the covering panel, in case the tongue extends overthe total lengths.

The tongue 13 is provided with a latching protrusion 19 at its bottomside 17 which preferably extends over the total length of the tongue andtherewith over the total length of the longitudinal edge of the coveringpanel 10. The complimentary provided groove 14, at the opposite side ofthe covering panel 10, has an upper flank 21 and a lower flank 22.Within the lower flank 22 a latching groove 23 extends, preferably alsoover the full length of the lower flank 22. As shown in FIG. 1, thelower flank 22 is slightly longer than the upper flank 21. In thismanner, the inserting of the tongue 13 into the groove 14 is easier, incase two covering panels 10 with complementary provided groove andtongue elements are joined with each other. While inserting the tongueinto the groove the latching protrusion 19 is pressed in the latchinggroove 23 in the lower flank 22 of the groove 14 which is preferablycomplementary provided. In this manner, two properly provided coveringpanels can be joined with each other particularly secure. Since, likeshown, the contacting means 15 and 20 respectively are arranged at thecoupling means, i.e. the tongue and also the groove, while joining twocovering panels mechanically, an electrical connection between theelectric contacting means 15 and 20 is automatically provided. Since thecontacting means are again in electric connection with the heating meansarranged on top or bottom side of the covering panel, like in thefollowing will be described, also an electric connection between theelectric heating means is created in a simple manner. Therefore, noaddition hand grips or tools are necessary in order to provide also theelectric contact between these panels, in addition to the mechaniclatching. Therefore, such a provided covering system can be laid bylayman.

In FIG. 2, a further embodiment of a covering panel 26 is schematicallyshown in cross-section. The same or similar parts are here and in thefollowing figures provided with the same reference signs. The tongue 13has electric contacting means 15 in form of a thin contact strip whichis arranged at the lower side of the tongue 13 and which extends to thebottom side of the covering panel 26. The lower flank of the groove 14is provided with a further contacting means 20 which extends also to thebottom side of the covering panel 26. In the embodiment of FIG. 2, thecontacting means cover the coupling means, i.e. tongue and groove, onlypartially. As can be clearly seen in FIG. 2, nevertheless, an electricconnection between two covering panels is provided in case the tongue 15of a covering panel is inserted into a complementarily provided groove14 of a further covering panel, since, in the present case, at least thelatching protrusion at the tongue and the latching groove in the lowerflank of the groove 14 is covered by the contacting means. At the bottomside of the covering panel 26 an electric heating means 24 which is incontact with the contacting means 15, 20 is arranged.

In the present case, the electrical heating means consists of anelectric panel heating. This, for example, can be made of anelectrically conducting thin layer which is built from electricresistant wires which are webbed in a carrier fleece. The electric panelheating can, however, also be made of an electrically conductingcoating, for example, a coating made of graphite varnish or carbonvarnish or a mixture thereof. Electrically conducting coatings can bemade of, for example, a fluid, which, after the covering panels areprovided with electric contacting means, is applied onto the bottom sideof the covering panel. This can be provided, for example, by means ofspray coating, coil coating, doctor blade coating, screen coating orinkjet coating or also by a combination of these methods. In order toincrease the electric conductibility of such a fluid, carbon or graphiteparticles can be included. Below the heating means 24, an optionalheat-insolating layer 25 is arranged which, for example, can be made ofan electrically non-conducting fleece. In order to provide a goodconnection of the layers, this heat-insolating layer can be, forexample, glued or sticked with the electric panel heating 24. The abovedescribed structure of the heating means can, of course, be providedwith power by means of other respectively conventional contacting meanswherein the herein described contacting means are preferred.

In FIG. 3 a schematic cross-section view of a further embodiment of acovering panel 30 is shown. At the top side of the covering panel 30three layers are schematically indicated. The upper-most layer consistsof an overlay 36, for example, a paper, which is provided with a phenolresin and abrasion resistant particles, for example, corundum particles,serving as protection layer. The middle layer is a décor layer 31, likeusually used with laminate panels in order to give the panels the lookof real wood parquet. An upper core layer 32 is arranged below.

Also at the bottom side of the covering panel 30 a layer system isarranged. The first layer at the bottom side of the covering panel 30 isa lower core layer 33. Below, a counter-strike paper 34 is arrangedwhich should prevent a counter-strike of the laminate panel, i.e. of thecovering panel 30. Below, a sound-absorbing layer 35, typically 0.3 mmthick, is arranged. The electric contacting means 15 and 20 extendspartially over the bottom side of the covering panel 30 and restpartially onto the protective layer 35. Below the sound-protective layer35 again, an electric heating means in form of a panel heating 24 isarranged. In FIG. 3 it can be clearly seen, like the ends of thecontacting means 15, 20 are in contact with the panel heating 24. Belowthe panel heating 24, similar as in FIG. 2, an optional heat-insolatinglayer 25 is arranged. For a person skilled in the art it is clear thatall layers are tightly bounded with each other in order to build acovering panel with a thickness of a few millimeters.

In FIG. 4 the structure of a further laminate panel 40 is schematicallyshown. With reference sign 43 a carrier panel, for example made of HDFor MDF material, is characterised which builds the structure core of thelaminate panel 40 as such. The upper-most layer is built by means ofoverlay and décor paper 41 respectively. Below a heating means in formof an electric panel heating 42 is arranged, i.e. between HDF-carrierpanel and the overlay and décor paper 41 respectively. Below the carrierpanel 43 a core layer made of natron paper 44 is arranged. Below, again,a counter-strike paper 45 and below a sound-absorbing layer 46 arearranged. As clear for a person skilled in the art, the electriccontacting means are able to connect such a laminate panel by which theheating means 42 are arranged at the top side of the panel. For thispurpose, the contacting means, like shown in FIG. 1, are simply directedto the top side of the covering panel so that they be in contact withthe heating means. However, in this case, it is not necessary that thecontacting means extends to the bottom side of the covering panel.

In FIG. 5 a heat-able covering system 50 is schematically shown. Thecovering system 50 consists of a number of covering panels, for examplethe covering panels 51, 52, and 53. As shown in FIG. 5, the coveringpanels are provided with electrical contacting means 54 whichessentially extends over the total longitudinal sides of the coveringpanels. As can be seen clearly, some of the covering panels are shorteras others. In order to adapt the covering system in its shape to therespective occurrences, for example, a room in which the covering systemshould be laid. Since the electrical contacting means extends over thetotal longitudinal side of the covering panel, the covering panels cansimply cut without that this has negative effects to the electricconnectability of the panels. With reference sign 55 an electro moduleis indicated which provides the electric power supply for the heatablecovering system 50. Such an inventiveness covering system has, amongothers, the advantage that it can be also laid by a layman due to thesimply electrical connectability of the electrical heating means.

In FIG. 6 a covering system 60 is illustrated which consists of a numberof three separated covering systems 61, 62, and 63 which each has an ownpower supply 64, 65 and 66 respectively. The modular structure of thecovering system 60 allows the use of more smaller power supply devices64, 65, 66 instead of a single large device. In this manner, insolatingtransformers with a power of typically several 100 W, for example 700 W,can be used which can be connected and installed, respectively, also bya layman without particular qualification. By a typical area power ofseveral 10 W per m² up to about 100 W per m², for example 10 m² area canbe supplied by means of such small transformers. Furthermore, the powersupply devices can be provided with a remote control and/or withtemperature sensors in order to simplify the operating and the handlingof the heatable covering system.

In FIG. 7 a schematic illustration of an alternative electricalcontacting means is shown. FIG. 7 shows schematically a covering panel70, looked from its bottom side. The covering panel 70 is provided withan electrical panel heating 71 which is provided according to the abovedisclosed electrical heating means. The electrical panel heating 71 is,for example, a thin film of an electrically conducting graphite orcarbon varnish. On the panel heating 71 two electrical contacting means72 and 73 are arranged. The contacting means 72 and 73 consists of, forexample, a thin conducting metal strip which is tightly connected withthe electric to panel heating 71, for example, glued. Also with thisalternative manner, the herein described electrical heating means can besupplied with power. However, for a person skilled in the art, it isclear that also further alternatives exist which cooperate with theelectrical heating means.

In periods in which it is not heated, an alternating power system withvery reduced power output or in an interval manner can be used, wherebycorrosion effects due to humidity or galvanic potential differences inelectrically conducting contacting means can be avoided. This form ofpreventive protection is particularly recommended while using directcurrent.

The mounting of the electrical contacting means on the coupling meanscan be carried out in different manners. For example, contacting stripsmade of thin copper or aluminium or high quality steel can be used whichare provided with an adhesive layer which preferably has electricallyconducting characteristics. Thereby, at first the panel heating layercan be applied and subsequently the electrical contacting means can beapplied or contrariwise. As materials for the electrical contactingmeans, for example, a conducting copper foil is suitable, for example,the “Conductor Copper Fuel Tape” VE1691 of the company D&MInternational, A-8451 Heimschuh. Further materials, for example, arefrom the company 3M Electrical Products Division, Austin, Tex., USA, forexample, the type 1183.

In an alternative way of production an electrically conducting thinfoil, for example, a copper or aluminium or high grade steel withoptionally an applicable surface coating is applied, for example, ontothe bottom side of a laminate panel at the edge in longitudinaldirection. That followed, that thin foil is pressed onto or around thecoupling means. The pressing preferably happens in such a manner that nosteps on the passage between the foil and panel surface appears. Afterthat a panel heating element can be applied onto the bottom side of thepanel wherein the panel heating element gets into contact with at leasta part of the foil. The electrical contact between the foil and heatingmeans can be improved by an additional pressing. In addition, thecontacting strips can be tint or nickel coated.

The electrical heating means can be used in form of an electricallyconducting paste, paint or varnish, respectively with suitable viscosityand dry characteristics. For example, carbon or graphite pigments with apolymeric matrix can be used. Since such a heating layer is only a fewmicrometers thick, different thermal expansions between heating layerand the other components of the covering panel do hardly not play arole.

The herein described electrical heating means are particularly goodapplicable in order to be combined with the disclosed contacting means.However, as a matter of course, it is also possible to supply theheating means over conventional electrical contacting means with powerso that the herein described electrical heating means can be usedindependent from the described contacting means.

The invention claimed is:
 1. A heatable covering system for floors,ceilings and walls, comprising: covering panels each having a decorativetop side and a bottom side; wherein the covering panels comprisingcomplementary edge couplers in order to join the covering panels to eachother, and wherein the covering panels each have electric heating meansand an electric contact arranged at least partially at the coupler sothat the contacts of two joined panels will establish an electricalconnection between the joined panels, and wherein the electric heatingmeans includes a panel heating element in the form of an electricallyconducting coating on each panel, the electrically conducting coatinghaving been formed by applying an electrically conducting fluid onto thepanel and drying the fluid, whereby the coating will be directly adheredto the panel.
 2. The heatable covering system according to claim 1,wherein the electrically conductive coating is at the bottom side of thecovering panels.
 3. The heatable covering system according to claim 1,wherein the complementary couplers include complementary groove andtongue elements.
 4. The heatable covering system according to claim 1,wherein the complementary couplers are provided on at least two oppositelongitudinal sides of the covering panels.
 5. The heatable coveringsystem according to claim 1, wherein the electrical contact of eachpanel substantially extends over the full length of the coupler.
 6. Theheatable covering system according to claim 1, wherein the electricalcontact of each panel includes a strip-shaped electrically conductingelement.
 7. The heatable covering system according to claim 1, whereinthe electrical contact of each panel includes a conductive elementpressed and/or glued on the coupler.
 8. The heatable covering systemaccording to claim 1, wherein the contacting means are attached to thecoupling means by means of an adhesive tape.
 9. The heatable coveringsystem according to claim 1, wherein the couplers include complementarygroove and tongue elements and the electrical contact of each panelincludes an electrically conducting metal foil, wherein the metal foilof one panel covers at least partially the inner surface of a lowerflank of the groove and the metal foil of the other panel covers atleast partially the lower side of the tongue.
 10. The heatable coveringsystem according to claim 1, wherein the electrically conducting coatingis formed of graphite lacquer or carbon lacquer or of a mixture thereof.11. The heatable covering system according to claim 1, wherein theelectrically conducting coating was applied by means of spray coating,coil coating, doctor blade coating, screen coating or inkjet coating orby a combination of these methods.
 12. The heatable covering systemaccording to claim 1, wherein the electrically conducting coating isprovided with carbon or graphite particles in order to improve theelectric conductivity.
 13. The heatable covering system according toclaim 1, wherein the electrically conducting coating comprisesnano-scale electric conducting particles ormulti-walled-carbon-nano-tubes.
 14. The heatable covering systemaccording to claim 1, wherein energy supply is carried out with analternating voltage smaller than 42 volt.
 15. The heatable coveringsystem according to claim 1, wherein a power input of 120 watt/m² is notexceeded.
 16. The heatable covering system according to claim 1, whereinthe covering system is provided with an automatic temperature control.17. The heatable covering system according to claim 1, wherein thecovering panels are laminate panels, veneer panels or parquet flooringpanels.
 18. The heatable covering system according to claim 1, whereineach panel includes thermal insulating layer.
 19. The heatable coveringsystem according to claim 1, wherein thermal insulating layer isarranged underneath the coating.
 20. The heatable covering systemaccording to claim 1, wherein below the heating means an thermalinsulating layer is arranged, which thermal insulating layer consists ofan electrically non-conducting nonwoven fleece, having a thickness ofmore than 1 mm.
 21. The heatable covering system according to claim 1,wherein the heating means has a sheet resistance of 100 to 500Ohm/quadrate.
 22. The heatable covering system according to claim 1,wherein the bottom side of the covering panel is provided with asound-absorbing layer.
 23. The heatable covering system according toclaim 1, wherein, starting from the bottom side of the covering panel,the following layer system is arranged: a sound-absorbing layer; theelectric heating means; an insulating layer.
 24. The heatable coveringsystem according to claim 6, wherein the electrical contact of eachpanel includes an electrically conducting metal foil.
 25. The heatablecovering system according to claim 12, wherein the electricallyconducting coating is provided with carbon or graphite particles inorder to make the coating electrically conducting.
 26. The heatablecovering system according to claim 16, wherein the automatic temperaturecontrol holds the surface temperature of the covering panels in therange of 18° C. to 32° C.
 27. The heatable covering system according toclaim 19, wherein the sound-absorbing layer is arranged beneath theelectrically conducting coating.
 28. The heatable covering systemaccording to claim 24, wherein the electrically conducting metal foil isformed of copper, aluminium or high grade steel.
 29. The heatablecovering system according to claim 24, wherein the electricallyconducting metal foil includes a tinned copper strip.